Vibrations acceleration values were achieved in the sensor mounting location, recorded every 0.488⋅10–3 s, as a result of
the measurements. The accelerations recorded contain information on vibrations corresponding to different forms [15]. This
derives from the fact that the slab bending line caused by loading with a concentrated force differed from the first form of
vibrations. The signal achieved was filtered with a low-pass filter with infinite impulse response (IIR). A curve of
acceleration ÿ(t) corresponding to the first form of free vibrations was produced as a result of the filtering operation.